Marcinkiewicz A3 vs Monette Unity D7-7
The Marcinkiewicz A3 has a wider cup diameter, the Marcinkiewicz A3 has a larger throat opening.
Cup Diameter
The Marcinkiewicz A3 has a cup diameter of 17.58 mm / 0.6921 in compared to 16.20 mm / 0.6378 in on the Monette Unity D7-7 — a difference of 1.38 mm / 0.0543 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
Both mouthpieces share a medium cup depth, so the sound character from depth alone will be very similar.
Throat Diameter
The Marcinkiewicz A3 has a wider throat (3.78 mm / 0.1488 in vs 3.66 mm / 0.1441 in). A wider throat allows more air through, increasing volume and projection but reducing resistance.
Which is better?
Neither mouthpiece clearly dominates the other — the right choice depends on your embouchure, playing style, and the sound you're after. Try both if possible.